Adhesive sealed solid electrolyte cell housed within a ceramic frame and the method for producing it

ABSTRACT

A solid electrolyte cell and method for producing it in which the cell components are assembled within a ceramic frame which is sealed on the top to a first terminal of the cell using an adhesive and sealed on the bottom to a second terminal of the cell using an adhesive and said second terminal having the opposite polarity to that of the first terminal.

This application is a division of prior U.S. application: Ser. No.07/982,622,filing date Nov. 27, 1992 now U.S. Pat. No. 5,314,507.

FIELD OF THE INVENTION

The invention relates to a method for producing a solid electrolyte celland the cell so produced, specifically a planar solid electrolyte cellhoused within a ceramic frame closed at the top surface and bottomsurface with conductive terminal sheets using an adhesive material. Thecell so produced will have high temperature stability and preferably behermetically sealed.

BACKGROUND OF THE INVENTION

Ionic conductivity is commonly associated with the flow of ions througha liquid solution of salts. In the vast majority of practical uses ofionic conductors, i.e., as electrolytes for dry cell and sealed leadacid batteries, the liquid solution is immobilized in the form of apaste or gelled matrix or is absorbed in a separator to overcome thedifficulties associated with handling and packaging a liquid. However,even after immobilization, the system is still subject to possibleleakage, has a limited shelf life due to drying out or crystallizationof the salts and is suitable for use only within a limited temperaturerange corresponding to the liquid range of the electrolyte. In addition,the use of a large volume of immobilizing material has hindered the aimsof miniaturization and lowers the output capacity.

Improved microelectronic circuit designs have generally decreased thecurrent requirements for each transistor which makes up the electronicdevices. This in turn has enhanced the applicability of solidelectrolyte power sources which usually can deliver currents only in themicroampere range. These solid electrolyte systems have the inherentadvantages of being free of electrolyte leakage, corrosion and internalgassing problems due to the absence of a liquid phase. In addition, theyalso have a much longer shelf life than the conventional liquidelectrolyte power sources.

In attempting to avoid the shortcomings of liquid systems, investigatorshave surveyed a large number of solid compounds seeking to findcompounds which are solid at room temperature and have specificconductances approaching those exhibited by the commonly used liquidsystems. Solid electrolytes must be essentially electronic insulators soas not to internally short the cell while at the same time they mustallow for ionic migration if the cell is to operate properly. There aremany solid state electrolytes "disclosed" in the art that can be usedfor solid state cells but many can only operate efficiently at highertemperatures, have low operating voltages or have internal highresistance.

United Kingdom Patent No. 2,201,287B discloses a solid polymerelectrolyte for use in solid electrolyte cells which comprises a complexof a solid polymer and an alkali metal salt, which polymer is capable offorming donor-acceptor type bonds with alkali metal ions and is capableof conducting alkali metal ions and wherein the complex is associatedwith a mixture of more than one substituted or unsubstituted1,3-dioxolane-2-ones. The preferred mixture recited is ethylenecarbonate and propylene carbonate. This solid electrolyte has been foundto produce a good lithium solid state cell that can operate at ambienttemperature.

U.S. Pat. No. 5,089,027 discloses a method for producing a solidelectrolyte cell using the solid electrolyte disclosed in the U.K PatentNo. 2,201,287B referred to above. In particular, an adhesive coatedframe is deposited on the peripheral area of current collector sheetsand the components of the cell are positioned within the frame ofadhesive whereupon the current collector sheets are then securedtogether at the peripheral area containing the adhesive layer.

Several cell applications require that the cell be directly incorporatedinto a device to produce a portable finished package. This could requirethe cell to be encapsulated or molded into the device. In injectionmolding, for example, the cell must be highly planar in appearance andcapable of withstanding high temperature processing up to 200° C. Theseconditions tend to favor the use of a solid electrolyte cell. Thepolymeric cell components such as the one referred to above, functionwell at elevated temperatures.

Flat solid electrolyte cells have been assembled typically with anadhesive coated substrate as a spacer and seal. The adhesive generallyused has melting points in the range of 80° C. to 105° C. andunfortunately, the seal integrity of the cells is subject to failure athigh temperatures.

It is an object of the present invention to provide a method forassembling a solid electrolyte cell within a ceramic frame in which theceramic frame functions as a housing for the cell components and saidframe is sealed to a conductive terminal sheet on each of its top andbottom surfaces using a high temperature adhesive seal.

It is another object of the present invention to provide a method forassembling a solid electrolyte cell within a ceramic frame, said cellemploying a solid electrolyte film containing poly(ethylene oxide) or apoly(ethylene oxide) type polymer in conjunction with ethylene carbonateand propylene carbonate.

It is another object of the present invention to provide an adhesivesealed solid electrolyte cell.

The foregoing and additional objects will become more fully apparentfrom the following description and drawings.

SUMMARY OF THE INVENTION

The invention relates to a method for producing a cell assembled such asa solid electrolyte cell assembly within a ceramic housing comprisingthe steps:

(a) preparing a first conductive terminal sheet and a second conductiveterminal sheet;

(b) forming a ceramic frame defining an opening at the center and havinga top surface and a bottom surface;

(c) preparing and assembling at least one cell assembly comprising ananode, a solid electrolyte separator and a cathode into the opening inthe frame; closing the top surface frame by securing the firstconductive terminal to the top surface of the frame using a hightemperature adhesive; closing the frame by securing the secondconductive terminal to the bottom surface of the bottom surface of theframe using a high temperature adhesive; and wherein said anode is inelectrical contact with one conductive terminal sheet and said cathodeis in electrical contact with the other conductive terminal sheet. Theinvention also relates to the cell so produced.

The high temperature adhesive for use in this invention shall maintainits adhesive characteristics at a temperature of at least 225° C.,preferably 250° C. and most preferably at 300° C. Samples of saidadhesives are any thermosetting adhesives that will not react with thecell components. Examples of suitable adhesives are phenolic rubber,polyvinyl butyral, epoxy polymers, and ethylene acrylic acid (EEA).Suitable commercial adhesives for use in this invention include aphenolic rubber adhesive available under the tradename Plymaster HT4033from Norwood Industries Inc.; a polyvinyl butyral adhesive availableunder the tradename Plymaster PM21 from Norwood Industries, Inc.; and anylon epoxy adhesive available under the tradename T-1401 from SheldahlCompany. The preferred adhesive is Plymaster HT4033 which is athermosetting adhesive. Generally, the high temperature adhesive shouldbe able to bond to dissimilar materials (such as ceramic-to-metal) witha high strength and have good resistance to moisture. The adhesiveshould maintain its bond when exposed to a temperature of 240° C.Although the surfaces of the ceramic frame do not require any surfacepreparation to be sealed to the conductive sheet using the adhesive, insome applications it may be preferable to treat the surface of the frameto improve its affinity for the adhesive. For example, the surface areaof the frame could be corona treated to increase the surface affinityfor the adhesive. The thickness of the adhesive layer needed to securethe conductive terminal sheet to the frame can be from 1.0 mil thick to10 mils or above. Preferably, the thickness should be from 1 mil to 5mils, and most preferably from 2 mil to 3 mils.

The first and second conductive terminal sheets may be made of anyconductive material suitable for functioning as a terminal for the cell.Examples of suitable conductive materials are copper, zinc, nickel,stainless steel, and nickel plated copper.

A ceramic frame, preferably an alumina-containing frame, is preparedwith an opening at its center. The width of the top and bottom surfacesof the frame should be sufficient so that when a first conductiveterminal sheet is placed on the top surface of the frame and a secondconductive terminal sheet is placed on the bottom surface of the frame,the superimposed areas of both conductive terminal sheets on the framewill be sufficient to contain the adhesive layer for securing the sheetsto the frame. Preferably, the active components of the cell should notcontact the adhesive layer. Once the conductive sheets are secured tothe frame, the sheets should preferably provide pressure contact to theanode and cathode components of the cell. Examples of a ceramic framesuitable for use in this invention could be selected from the groupconsisting of alumina, BeO, SiC, AlN, Si₃ N₄, SiO₂, glass, and mixturesor composites thereof. The preferred ceramic would be analumina-containing ceramic. The thickness of the ceramic frame should beselected so that when the cell components are placed within the ceramicframe, the cell components will completely fill the frame and extend atleast to the surface of the frame or beyond. This will insure goodelectronic contact between the cell components and the conductiveterminals secured to the frame.

The preferred alumina-containing alloys for the ceramic frame wouldcomprise 92% to 99% by weight alumina with 93% to 96% weight aluminabeing the most preferred. In another embodiment, the top surface andbottom surface of the frame could be coated with a metal or metal alloyto provide a physical bond with the ceramic material while alsoproviding a surface onto which the adhesive can be deposited. Suitablemetal coating for the frame would be copper, gold, molybdenum, silver,and platinum. Suitable metal alloys would be a molybdenum-manganesealloy. The preferred initial coating on the frame could be moly-Mg andthis coating can be sintered onto the top and bottom surface of theframe. Generally, the metal or metal alloy could be pasted or platedonto the frame surfaces. The primary purpose of the initial coating onthe surfaces of the frame is to provide a good physical ceramic to metalbond.

The opening in and the thickness of the ceramic frame will depend on thevolume of the components of the cell that will be assembled within theframe. As discussed above, the components of the cell shall at leastfill the opening in the frame so that when a conductive terminal ispositioned on each side of the frame, each conductive terminal willelectrically contact a component of the cell. Preferably the componentof the cell should be in pressure contact with the conductive terminals.The configuration of the frame could be square, rectangular, circle orany polygonal shape configuration such as a square frame having anextended tab which could be used as an indexing means. The tab could bean integral part of the unit or a separate part secured to the frame.Preferably, the size of the terminal sheets should be the same as thesize of the frame so that when the terminal sheets are placed over thetop and bottom surfaces of the frame, they will all be aligned. Thus thesize of the opening and the thickness of the frame will be a primaryfactor in determining the cell's output capacity. In some applicationsone of the sheets may have an extended tab that could be folded over theother sheet and insulated from the other sheet so that both terminals ofthe cell could be on the same side. Alternatively, one sheet may beslightly smaller in size than the frame at a selected area so that athrough hole could be placed in the uncovered portion of the frame andextend to the sheet on the opposite side. A conductive material, such ascopper, conductive epoxy or a conductive eyelet, could be disposed inthe opening of the ceramic so that it could make electrical contact witha conductive sheet secured over one side of the frame and extend abovethe surface of the opposite side of the frame so that both terminalscould be on the same side of the cell.

Although many solid electrolytes can be used in this invention, thepreferred solid electrolyte separator is one fabricated from acomposition of poly(ethylene oxide), referred to hereinafter as PEO,along with a lithium salt, the anion of which may, for example, be I⁻,Br⁻, ClO₄ ⁻, SCN⁻, BF₄ ⁻, PF₆ ⁻ or CF₃ SO₃ ⁻. Added to this compositionis ethylene carbonate and propylene carbonate. It has been found thatethylene carbonate is better than propylene carbonate as an electrolytesolvent because it has a higher electric constant, but has thedisadvantage, for use in a liquid system, that it is solid at roomtemperature. Thus, for solid electrolyte applications, ethylenecarbonate would be the desired choice. However, it was discovered inU.S. Pat. No. 5,041,199, that the addition of propylene carbonate alongwith ethylene carbonate to a poly(ethylene oxide)-containing solidelectrolyte will effectively lower the temperature at which the polymerundergoes a transition from an amorphous form to a crystalline formthereby substantially eliminating the presence of a crystalline form ofthe polymer at temperatures above about 20° C. This composition of asolid electrolyte is excellent for use in a solid electrolyte cell thatcan function at temperatures of about 20° C and above.

The preferred polymeric solid electrolyte film for use in this inventionfunctions as a physical barrier between the anode and the cathodematerial, as well as, being ionically conductive at temperatures of 20°C. The preferred composition of the solid electrolyte separator would bePEO-70wt/%(3EC-1PC)₂₀ LiClO₄. The preferred preparation of the polymericsolid electrolyte would be as follows:

A desired quantity of ethylene carbonate is dissolved with propylenecarbonate in a small beaker. The beaker is covered and set aside untilthe ethylene carbonate is dissolved completely. The beaker may be heatedslightly (50° C.) to expedite the process. Dried poly(ethylene oxide) iscombined in a high density polyethylene bottle containing 3/4 inchdiameter ceramic mixing balls with isopropyl alcohol. The solution alongwith a metal salt, ethylene carbonate, propylene carbonate, and asolvent can then be ball milled for a time period such as 30-45 minutesuntil a smooth viscous mixture is formed. The mixture can then be setaside for degassing.

The polymeric electrolyte solution can then be cast onto a release papersuch as a polyethylene or silicone coated release paper. The film isthen allowed to dry for example about 2 hours. The film can then betransferred into a controlled temperature and humidity atmosphere (dryroom) to complete the drying cycle. The material should have a moisturecontent less than about 30, preferably less than about 20 ppm H₂ O forbattery use. Higher moisture levels result in a tacky film with poormechanical properties. In addition, a latent reaction between the waterand the salt (for example LiClO₄), the water and the lithium and/or thewater and the solvent may also occur in a sealed cell if the watercontent is too high.

The molecular weight of the PEO can vary from 600,000 to 5,000,000. Theproportions of the EC to PC could vary between 3.4 to 0.5 and 0.5 to3.5. The amount of the PEO component of the solid electrolyte could varyfrom 30 to 50 weight percent. Suitable solvents for use in preparing thesolid electrolyte could be acetonitrile, methanol, tetrahydrofuran(THF), isopropyl alcohol, dichloromethane and the like.

The cathode material for use in this invention can contain an activecathode material such as manganese dioxide (MnO₂), carbon monofluoride,vanadium pentoxide, metal chromate such as silver chromate and silverbismuth chromate and silver vanadium chromate; metal oxide such asnickel oxide, lead oxide, bismuth lead oxide and copper oxides; sulfidessuch as copper sulfides and iron sulfides; and cadmium. A carbonaceousmaterial, if used, should preferably be carbon. The preferredcarbonaceous material is acetylene or furnace black. The cathodematerial should also contain the same material as the electrolyte suchas poly(ethylene oxide) with a lithium salt, the anion of which may, forexample, be I⁻, Br⁻, ClO₄ ⁻, SCN⁻, BF₄ ⁻, PF₆ ⁻ or CF₃ SO₃ ⁻, along withethylene carbonate and propylene carbonate. The solvent for the cathodecould be methanol, trichloroethylene and the like. The preferredpreparation of the cathode material would be the following:

A quantity of ethylene carbonate can be dissolved with propylenecarbonate in a small beaker. The container could then be covered and setaside until the ethylene carbonate is completely dissolved. The beakermay be heated slightly (50° C.) to expedite the process. Pre-treatedmanganese dioxide and carbon could be mixed in their dry states in ahigh density polyethylene bottle with 3/4 inch diameter ceramic mixingballs for one hour. Upon completion of the dry blend, a solvent such asmethanol can be added. The mix can then be milled for about 1 hour. Asecond quantity of a solvent such as methanol and dried poly(ethyleneoxide) can then be added slowly, alternating between small additions ofliquid and dry materials, shaking vigorously between each combination.Next a salt such as a LiClO₄ salt can be added and the compositionshaken once again. Finally, a second solvent, such as trichloroethylene,the dissolved EC/PC solution and a dispersant such as sorbitanmonooleate, can be blended into the previous manganesedioxide-containing mixture and then can be milled for one hour. Thecomposite can then be degassed and cast onto a coated release papersubstrate such as polyethylene. The film can be allowed to dry for about2 hours. The film can be transferred in a controlled temperature andhumidity atmosphere (dry room) to complete the drying cycle. Thematerial should have a moisture content less than about 30, preferablyless than about 20 ppm H₂ O for cell-use. Higher moisture levels resultin a tacky film with poor mechanical properties. In addition, a latentreaction between the water and LiClO₄, the water and the lithium and/orthe water and the solvent may also occur in a sealed cell if the watercontent is too high.

Additional EC and PC may be added to the cathode material prior to itsassembly into a cell to replace any of the EC/PC that may have been lostduring the drying step. Also additional EC/PC should be added tofacilitate the proper contact with the conductive terminal since EC/PCwill make the cathode material somewhat tacky.

The conductive terminal sheet for use in this invention could be copper,nickel, stainless steel or the like, with copper being the preferredcurrent collector and more preferably the copper could be surfacetreated to enhance its affinity for adhesion to metal alloy solder. Forexample, the copper could be electrodeposited so that the surface wouldbe roughened. Preferably the thickness of the conductive terminal formost applications could be from 0.0005 to 0.003 inch thick.

The anodes for use in this invention are lithium, lithium alloys,calcium, sodium and potassium with lithium and lithium alloys being thepreferred.

The solid electrolyte cell may be encapsulated in various laminates toprovide additional protection for the cell. However, if the cell isencapsulated in a film such as a polyamide, mylar or metalizedpolyethylene film, then provisions should be made so that electricalcontact can be made from outside the cell to the conductive terminals ofthe cell. This could be accomplished by providing an opening in the filmthereby exposing a selected area of each of the conductive terminals.

As stated above, the cell of this invention can be encased orencapsulated between layers of a plastic material in which the cellbecomes embedded within said material as an integral part of material.Generally, this encapsulation involves a combination of high pressure atelevated temperature of as high as 200° C. The alumina-containingceramic housing of this invention is capable of withstanding flexuralpressures up to 50,000 psi, preferably at least 25,000 psi; compressivestrength of 130,000 psi or higher, preferably 300,000 psi; tensilestrength of 15,000 psi or higher, preferably 25,000 psi and withstand atemperature of 1300° C., preferably, 1700° C. For example, the cell ofthis invention could be encapsulated in a printed circuit board so thatthe printed circuit board along with other electronic components couldprovide a self-contained power electronic device.

The present invention will become more apparent from the followingdescription thereof when considered therein with the accompanyingdrawings which are set forth as being exemplary of an embodiment of thepresent invention and are not intended in any way to be limitativethereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is perspective view of a copper sheet (terminal) having anadhesive layer at the peripheral area on the top side of the sheet.

FIG. 1b is a perspective view of a ceramic frame defining an opening atits center and in which the copper sheet of FIG. 1a is secured to thebottom side of the ceramic frame.

FIG. 1c is a perspective view of an anode sheet for use in the cell ofthis invention.

FIG. 1d is a perspective view of the ceramic frame of FIG. 1b in whichthe anode sheet of FIG. 1c is shown disposed in the opening of theceramic frame to make contact with the copper sheet.

FIG. 1e is a perspective view of a separator for use in the cell of thisinvention.

FIG. 1f is a perspective view of the ceramic frame of FIG. 1d in whichthe separator of FIG. 1e is shown disposed in the opening of the ceramicframe to make contact with the anode.

FIG. 1g is a perspective view of a cathode for use in the cell of thisinvention

FIG. 1h is a perspective view of the ceramic frame of FIG. 1f in whichthe cathode of FIG. 1g is shown disposed in the opening of the ceramicframe making contact with the separator.

FIG. 1i is a perspective view of a copper sheet (terminal) having anadhesive layer at the peripheral area on the underside of the sheet.

FIG. 1j is a perspective view of the ceramic frame of FIG. 1h in whichthe copper sheet is secured to the top surface of the ceramic framemaking contact with the cathode and producing an assembled cell.

FIG. 2 is a cross-sectional view of a solid electrolyte planar cellproduced using the method of this invention and as described inconjunction with FIGS. 1a to 1j.

FIG. 3 is a perspective view of an assembled cell of this invention inwhich the bottom copper terminal has an extended tab folded onto andinsulated from the top copper terminal so that both terminals of thecell are on the top side.

FIG. 4 is a perspective view of an assembled cell of this invention inwhich one end of the cell is cut off.

FIG. 5 is a perspective view of an assembled cell of this invention inwhich a square ceramic frame has an extended protrusion on one of itssides.

FIG. 6 is a perspective view of an assembled cell of this invention inwhich the top terminal sheet exposes a selected area of the ceramicframe so that a through hole placed in the ceramic frame contains aconductive material that makes electrical contact with the bottomterminal sheet and extends above the top surface of the ceramic frame sothat both terminals of the cell are on the top side.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1a to 1j show a first conductive terminal sheet 2, preferablycopper, onto which is coated an adhesive 6 on one side of terminal sheet2 at its peripheral area 4. A ceramic frame 8, shown in FIG. 1b, has anopening 10 with a perimeter equal to the perimeter of terminal sheet 2so that when sheet 2 is superimposed on frame 8, they are completelyaligned. The top surface 12 and the bottom surface 14 of ceramic frame 8are made to accommodate the high temperature adhesive coating onterminals 26 and 2, respectively. The width X of frame 8 is the same asthe width Y of sheet 2 so that when frame 8 is placed on sheet 2, theuncovered inner surface of sheet 2 will be free of any high temperatureadhesive. With frame 8 aligned onto sheet 2, sheet 2 is secured to frame8 using an adhesive at an appropriate temperature, pressure and timeperiod. For example, when using Plymaster HT4033 adhesive, sheet 2 couldbe secured to the frame 8 at a temperature of about 200° C. and with apressure about 1000 psi for a time period of about 30 seconds.Thereafter an anode 20 (FIG. 1c), preferably lithium, sized slightlysmaller than the opening 10 in frame 8 is placed in frame 8 andelectrically contacts the surface of sheet 2 as shown in FIG. 1d. Ifdesired, a ram or ultrasonic means could be used to apply pressure tosecure contact of the anode 20 to sheet 2. A solid electrolyte separator22 (FIG. 1e), preferably a PEO separator, is placed within opening 10 offrame 8 over anode 20 as shown in FIG. 1f. Preferably the separator 22would be slightly larger than opening 10 so that the excess will form acup-like shape when pressed on top of anode 20 and thereby provide anadditional protection against internal shorting along the edges.

Next a suitable cathode composite 24 sized equal with opening 10 inframe 8 is pressed into opening 10 shown in FIG. 1h. As stated above, itis important that the thickness of anode 20, separator 22 and cathode 24is sufficient to completely fill the depth of opening 10 in frame 8 inorder to insure good contact with the conductive terminal sheets. Afterassembly of the cathode 24, a second conductive terminal sheet 26,identical to sheet 2 and also having an adhesive layer 6, is placed overframe 8 and sealed to frame 8 in a manner as described above for sheet2. An assembled cell 30 is now produced as shown in FIG. 1j. Using themethod of this invention, a cell can be produced having any desiredcapacity depending on the volume of the opening in the frame. The cellso produced will be a rigid cell capable of functioning at hightemperatures and therefore ideally suited for being encapsulated ormolded into various devices, boards, or electronic housings.

FIG. 2 shows a cross-sectional view of the solid electrolyte cell 30produced as described in conjunction with FIGS. 1a to 1j and hasidentical components identified with the same reference numbers.Specifically, FIG. 2 shows a solid electrolyte cell 30 comprising acathode material 24, solid electrolyte separator 22 and anode 20disposed within opening 10 of frame 8. Anode 20 is in pressure andelectrical contact with conductive terminal sheet 2 which in turn issecured by adhesive 6 to frame 8. Cathode 24 is shown in pressure andelectrical contact with conductive terminal sheet 26 which in turn issecured by adhesive 6 to frame 8.

FIG. 3 shows an assembled cell 31 in which the bottom conductiveterminal 32 has an extended tab 34 which extends over and onto topconductive terminal 36. An insulating material 38 is placed betweenterminal 36 and tab 34 so that both terminals 36 and 32 are on the topside of the cell.

FIG. 4 shows an assembled cell 40 in which the end 42 is removed toprovide a polarization key for the cell.

FIG. 5 shows an assembled square cell 50 in which one side has anextended protrusion 52 which is adapted to sit within a similar cavityin a battery powered device.

FIG. 6 shows an assembled cell 60 in which a portion of the topconductive terminal 62 is removed exposing a conductive lined or filledthrough opening 64 which makes electric contact with conductive terminal66. Thus, both terminal 60 and terminal 66 are on the top surface of thecell.

The overall assembled cell produced can be used to operate anyelectrical device designed to operate at the cell's output potential.Although not shown, the cell could be encased in an enclosure such as aplastic enclosure having appropriate openings so that electrical contactcould be made to both current collectors. The flat cell so producedoccupies only a relatively small space and therefore can accommodate avariety of small battery operated devices. The cell can be fabricatedwith various output capacities and sizes to accommodate variouselectrical devices.

EXAMPLE

A sample cell was made using the procedure as described in FIGS. 1a to1j. The cathode material was made from a composition as follows:

40.0 grams of heat treated manganese dioxide

2.28 grams of heat treated carbon

23.36 grams of ethylene carbonate dissolved with 9.04 grams of propylenecarbonate

4.0 grams of LiClO₄ salt

15.56 grams of poly(ethylene oxide) (PEO)

240 ml of methanol

320 ml of trichloroethylene

0.24 grams of SPAN 80 which is a trademark for sorbitan monooleate ofICI, Atlas Chemical Division of United States

A thin piece of a solid electrolyte (separator) was produced having thefollowing composition:

21.60 grams of a complex of poly(ethylene oxide)

5.16 grams of a lithium salt, LiClO₄

37.80 grams of ethylene carbonate

12.60 grams of propylene carbonate

75 ml of isopropyl alcohol

460 ml of acetonitrile

A 6 mils thick piece of lithium was used as the anode.

The cell was assembled as described with reference to FIGS. 1a to 1jusing a 96% alumina frame. The conductive terminal sheets were copperand coated on their peripheral surface with a thermosetting adhesive (aphenolic rubber) obtained under the tradename Plymaster HT4033. Thethickness of the adhesive was 3 mils and the terminal sheets weresecured to the frame at a temperature of about 200° C. with an appliedpressure of about 1000 psi for about 30 seconds. The open currentvoltage was 3.45 volts. The closed circuit voltage was 3.43 volts.

It is to be understood that modifications and changes to the preferredembodiment of the invention herein described can be made withoutdeparting from the spirit and scope of the invention. For example,bipolar batteries could be constructed to produce higher voltages. Forexample, in FIG. 2 if two batteries were placed on top of each otherwith one of the conductive terminals (current collectors) removed, thena bipolar battery would be constructed consisting of a conductiveterminal 2, anode 20, separator 22, cathode 24, another conductiveterminal 2, if desired, another anode 20, another separator 22, anothercathode 24 and a final conductive terminal 26.

What is claimed:
 1. A cell comprising a ceramic frame defining an opening and having a top surface and a bottom surface; a first conductive terminal sheet secured by an adhesive to and closing the bottom surface of the frame; a second conductive terminal sheet secured by an adhesive to and closing the top surface of the frame; and an anode, electrolyte and cathode assembly within the opening of the frame and arranged so that the anode makes electrical contact with one conductive terminal sheet and the cathode makes electrical contact with the other conductive terminal sheet.
 2. The cell of claim 1 wherein the anode is lithium, and the cathode is MnO₂.
 3. The cell of claim 1 wherein said top surface and said bottom surface are corona treated surfaces.
 4. The cell of claim 1 wherein said top surface and said bottom surface has a metal or metal alloy layer. 